1. Technique Field
The invention relates to a nonreturn valve, in particular for medical uses.
2. Related Art
A nonreturn valve of this type, according to an earlier proposal by the applicant, is known from German utility model 20 2006 016 730.7.
These types of nonreturn valves for the medical field are required in infusion systems, diagnostic equipment, intravenous tube lines and the like, and therefore these types of nonreturn valves have to close in a very reliable manner and the closing time must be only fractions of seconds, in order thereby to avoid any backflow of liquids charged with undesired substances. Moreover, at the same time, production not only has to be extremely economical but also statistically very accurate, since valves of this kind can be used for medical applications exclusively as disposable articles and consequently, for cost reasons, have to be produced in very large numbers in an automated manner. At the same time, there are very strict legal regulations in respect of constant and uniform functional reliability, which is carefully monitored in Germany for example by the Technical Inspection Agency.
A valve of the abovementioned type is an improvement on a nonreturn valve according to another earlier proposal by the applicant, known from German utility model 20 2004 009 358.8, and thus ensures that, when there are high pressures on the inlet side of the valve, a situation can no longer arise where the openings provided in the diaphragm are able to bear on the opposite wall of the outlet chamber because of this overpressure and thus cause the valve to unintentionally close. This improvement is achieved by the numerous supporting surfaces between the recesses, which supporting surfaces ensure that, in the area of the openings in the diaphragm disk, a connection to the outlet chamber is maintained in any case, even if the diaphragm disk were to bear fully on the supporting surfaces.